From Longman Dictionary of Contemporary Englishuniformu‧ni‧form1 /ˈjuːnəfɔːm $ -ɔːrm/ ●●●S3 noun [countable, uncountable]1DCCa particular type of clothing worn by all the members of a group or organization such as the police, the army etcschool/army/police etc uniformHe was still wearing his school uniform.2 →in uniform